Carta marina, a wallmap of Scandinavia, by By Olaus Magnus, via Wikimedia Commons.

 

 

Zoom OpenSeadragon is an implementation of OpenSeadragon, an open-source, web-based viewer for high-resolution zoomable images, implemented in pure JavaScript, for desktop and mobile..

It is released under the New BSD license that is also used for OpenSeadragon, so feel free to download, modify and work on it.